Along with nagging mysteries and big reveals, romances have always been key to keeping fans of ABC Family’s “Pretty Little Liars” buzzing. But for “Ravenswood,” a new spinoff of the most popular series on Twitter, the writers decided to add some experiments with male-female friendships.

Exhibits A and B: The characters Caleb (played by Tyler Blackburn) and Miranda (Nicole Gale Anderson). After meeting on a bus out of Rosewood, the setting of “PLL,” they become sidekicks in the spinoff’s first episode (airing Tuesday) as they start to uncover their twisted roots in the creepy town of Ravenswood. “For me it was fun to explore this ‘When Harry Met Sally’ idea–can a guy and girl be friends without being boyfriend and girlfriend?” says I. Marlene King, the “PLL” showrunner who co-created and executive produced “Ravenswood.”

Of course, it wouldn’t be part of the “PLL” family if there weren’t some love birds whose names could be smushed together by fans. King says she is “fairly certain that #Lemy will be the first trending topic for ‘Ravenswood.’ We asked our fans via Twitter to come up with a hashtag name for the couple of Luke and Remy and they decided on #Lemy.” (Luke is the sulky son of a suspected murderer, and his girlfriend Remy works for her father at the local newspaper, a surprisingly retro institution given the “PLL” focus on digital communication.)

ABC Family put the spinoff into motion after last year’s “PLL” Halloween special, and officially announced “Ravenswood” last March. That gave the writers just enough time to sprinkle new characters and plots into “PLL” that could later jump to the new show. One of them was Carla Grunwald (played by Meg Foster). An older woman with steely blue eyes, she first appeared as a sorority-house mother and revealed a grave connection to the character at the core of the “PLL” mystery, Alison DiLaurentis.

Carla, who materializes again in the first episode of “Ravenswood,” will play a significant role in the spinoff because she “has a secret that Caleb needs to uncover,” King says.